I’ve complained before about the modern era’s overhasty dismissal of Aristotle – or at least my high school’s overhasty doctrine of the dismissal of Aristotle. First of all, the man known in the Middle Ages as The Philosopher did the best he could with the observational tools (or lack thereof) that he had. In fact, he did the best anybody could have. How can anybody deny that the man’s mind was quick, penetrating, and visionary? Secondly, his work in logic, ethics, rhetoric, and poetics still fuels serious discussion, even where scholars have disagreed or refined his theories. And finally, his scientific ideas weren’t always that crazy – or even wrong. He said the heavier ball drops faster, and, despite a few decades of science saying he was wrong, we now have to acknowledge that he was right. Come to think of it, why would anyone have thought that we’re obligated trust Leonardo’s eyesight more than Aristotle’s reasoning? It seems modern science (again, as represented by my hopeless high school) believes that no one in the ancient world understood the importance of observation.
Or consider Aristotle’s four elements: earth, water, air, and fire. “What a simpleton!” my high-school faculty snickers collectively. “True science has shown us that the elements number over a hundred.” But I’m not so sure Aristotle’s “element” meant the same thing as our “element.” Aristotle described an element as a manifestation of the underlying matter, as one of four states that matter could be in. Any element could change into others under the proper and rather common conditions. Well, modern science doesn’t believe that elements routinely change into others; otherwise, we’d all be alchemists turning iron into gold. But modern science does tell us that matter can be in one of four states – solid, liquid, gas, and plasma – and that almost any given piece of matter can change from one state to another given a change of temperature. Now I know they’re not the same thing, but aren’t earth, water, air, and fire fascinatingly similar to solid, liquid, gas, and plasma?
So I’ve enjoyed reading Aristotle over the years and trying to see him in the best light, trying to concoct ways of seeing his science as almost true, or true enough for practical purposes. But in reading On the Heavens, I’ve come across some theories that I can’t save. According to Aristotle, Heaven is a sphere made of a fifth, indestructible element. The space between Earth and Heaven is filled with a layer of air and then a layer of fire. (By fire, he means not necessarily flame but a combustible “exhalation.”) The Earth sits unmoved at the center of the universe, and Heaven spins around it. The friction between Heaven and the layer of fire often ignites parts of the fiery sphere, and thus we get comets and shooting stars.
I was amazed to find Aristotle reporting that the Pythagoreans say that fire sits at the center of the universe and that the Earth revolves around the fire and creates the appearance of day and night by spinning on an axis once every twenty-four hours. So, the modernist in me says, if Aristotle had really been an intelligent scientist, he would have jumped on this idea, tested it by observation and reason, and found the Pythagorean model better than the model of the rotating heavnely spheres a couple of millennia ahead of Copernicus. I was even more amazed, though, to read his reasons for rejecting the theory of Earth’s rotation. The Pythagoreans, he explained, can’t account for all the phenomena and instead simply choose the observations that fit their pet theory without testing it as far as it can go. So he had something like a modern scientific rationale for rejecting the more modern scientific model.
And this means that Aristotle in fact understood quite well the role of observation in scientific explanation. Anyone who thinks he doesn’t value observation just hasn’t read enough Aristotle in other words, there is a lack of observation, but not on the part of the ancient Greek. In his Meteorology, I recently read another indication of the role of observation in Aristotle’s scientific reasoning. As an introduction to the topic of comets, he says, “We consider a satisfactory explanation of phenomena inaccessible to observation to have been given when our account of them is free from impossibilities.” Is this Sherlockian stance a little too complacent? Perhaps. But it acknowledges the necessity of observation. The man who tried to figure out everything admits that his theory about comets may be completely wrong, but it implies that it will simply have to do until someone can get closer to one and get a better look.